/*
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 *    InstanceQueryAdapter.java
 *    Copyright (C) 2011-2012 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.experiment;

/**
 * An interface implemented by InstanceQuery and any user class that is to be
 * passed as the first argument to
 * InstanceQuery.retrieveInstances(InstanceQueryAdapter, ResultSet).
 *
 * @author Wes Munsil (wes_munsil@cytoanalytics.com)
 * @version $Revision$
 */
public interface InstanceQueryAdapter {
    /**
     * returns key column headings in their original case. Used for those databases
     * that create uppercase column names.
     *
     * @param columnName the column to retrieve the original case for
     * @return the original case
     */
    public String attributeCaseFix(String columnName);

    /**
     * Gets whether there should be printed some debugging output to stderr or not.
     *
     * @return true if output should be printed
     */
    public boolean getDebug();

    /**
     * Gets whether data is to be returned as a set of sparse instances
     * 
     * @return true if data is to be encoded as sparse instances
     */
    public boolean getSparseData();

    /**
     * translates the column data type string to an integer value that indicates
     * which data type / get()-Method to use in order to retrieve values from the
     * database (see DatabaseUtils.Properties, InstanceQuery()). Blanks in the type
     * are replaced with underscores "_", since Java property names can't contain
     * blanks.
     *
     * @param type the column type as retrieved with
     *             java.sql.MetaData.getColumnTypeName(int)
     * @return an integer value that indicates which data type / get()-Method to use
     *         in order to retrieve values from the
     */
    public int translateDBColumnType(String type);
}
